I am using Mediamonkey 4.1.13.18.01 on Windows 10 Pro and the MediaMonkey App on another Windows 10 Notebook.
I want to sync music to the App and ratings and playcounts back to MM.
This is partly working.

Here are my problems:

FLAC files are not synced at all. They are shown as syncing, but even after some hours it was still syncing the same song.

The sync sometimes gets stuck at "Syncing playlists to server", for hours

Ratings and playcounts are not synced back to MM.

I have activated the sync of metadata from the device to the PC in the sync profile.